My Rye/Wheat IPA (8%ABV, 88 IBU, 65 degrees F) spent two months in the secondary, and this white film started surfacing at the top of the beer's surface in carboy. It didn't change colors, tasted like yeast, but looked like mold forming. I bottled immediately but am not sure of what I have nor what to expect for shelf life, was going to wait a couple more weeks before sampling & maybe dumping. All the samples I've done with this have been great so far.

Thanks!

Easiest to throw out a little Palmer:

10.3 AutolysisWhen a yeast cell dies, it ruptures - releasing several off-flavors into the beer. When you have a large yeast mass on the bottom of the fermentor, you have a large potential for off-flavors due to autolysis. If this ever happens to you, you will know it. The smell is one you will never forget.

Luckily, the propensity of yeast to autolyze is decreased by a decrease in activity and a decrease in total yeast mass. What this means to a brewer is that racking to a secondary fermenter to get the beer off the dead yeast and lowering the temperature for the long cold storage allows the beer to condition without much risk of autolysis. At a minimum, a beer that has experienced autolysis will have a burnt rubber taste and smell and will probably be undrinkable. At worst it will be unapproachable.

As a final note on this subject, I should mention that by brewing with healthy yeast in a well-prepared wort, many experienced brewers, myself included, have been able to leave a beer in the primary fermenter for several months without any evidence of autolysis. Autolysis is not inevitable, but it is lurking.

Some of us-Bonjour-have kept it on the yeast for 2 years!

Also, sounds like you may have developed some mold. You'll know in a couple of weeks!

Figured it had to be a high gravity beer. 6 years! That is sweet! Cool story.

The rest of the story,Originally brewed much smaller, but my mash temp thermo was reading 10F low. Changed it to an experimental and kept adding various sugars until the gravity quit dropping after the additions. FG 1.065

I have experienced problems in primary with leaving the beer on the yeast in the high 60's/low 70's upwards of 6 weeks. First you will begin to taste a "brothy" or meaty component. Then you will see a noticeable darkening of the beer. To me this ruins the finished product.

This has happened several times when procrastination over-ruled my better instincts. It would be better to transfer to secondary and chill or even better- rack to a keg. Bottles also are suitable.

What it boils down to is it is better to get the beer off the yeast cake sooner rather than later. While there are exceptions it is best practice to do this within 20 days. That's nearly three weeks and for a "normal" average strength beer this amount of time is quite sufficient.

Logged

The first principle is that you must not fool yourself, and you are the easiest person to fool. -Richard P. Feynman

Laws are spider-webs, which catch the little flies, but cannot hold the big ones. -Anacharsis

For what it's worth, to reinforce the point that some others have made, I have also had beers that have aged on the primary yeast cake for well over 6 months and have NEVER had any off flavors from autolysis. I think the old conventional wisdom was due to the quality of yeast at the time. As long as you use healthy yeast, pitch enough yeast, and take care of them (maybe buy them dinner afterwards), you will not have any problems. If you stress out the yeast and have an unhealthy fermentation, I would think you could easily run into problems. For me, however, the risk of oxygenation during a transfer (which is unavoidable to some extent) far outweighs the risks of autolysis.

My Rye/Wheat IPA (8%ABV, 88 IBU, 65 degrees F) spent two months in the secondary, and this white film started surfacing at the top of the beer's surface in carboy. It didn't change colors, tasted like yeast, but looked like mold forming. I bottled immediately but am not sure of what I have nor what to expect for shelf life, was going to wait a couple more weeks before sampling & maybe dumping. All the samples I've done with this have been great so far.

Thanks!

Also, sounds like you may have developed some mold. You'll know in a couple of weeks!

Hope this helps.

Dave

If it smells good and is not fuzzy the white film could also be a pellicle from brett of lacto (pedio maybe?)

If it smells good and is not fuzzy the white film could also be a pellicle from brett of lacto (pedio maybe?)

Can you expand on this? Have not read or run in to. Thanks!

Dave

far from an expert but... there is a great loooong thread about this on homebrewtalk forum as well. several wild yeasts as well as a variety of bacteria will form a pellicle at the liquid air interface to protect themselves from o2. Brett does this and on a another thread on this forum someone indicated that aceto can do it as well, so it could be good or vinegar (which might still be good!) I have seen pictures of pellicles that look like a dusty whitish film on the beer. In fact I have a starter in my fridge right now that I made by putting a little piece of plum skin into a couple of ounces of wort I have left over from another starter that I think might be the same thing. It's not fuzzy like mold would be so I am hopefull. Assuming it doesn't just die in the fridge before I get to use it i will try pitching it into something else in a week or so.

follow-up. My batch of Rye/Wheat IPA did go bad, and I do think it was a Brett-like infection. Unlike a single strain of Brett, it was completely revolting. It tells me that longer than 2-3 weeks in secondary is not a good idea unless lagering in cold temps & then kegging.

follow-up. My batch of Rye/Wheat IPA did go bad, and I do think it was a Brett-like infection. Unlike a single strain of Brett, it was completely revolting. It tells me that longer than 2-3 weeks in secondary is not a good idea unless lagering in cold temps & then kegging.

It's not the time spent in the secondary, it's the sanitation of the equipment that makes the difference.

Logged

Jeff Gladish, Tampa (989.3, 175.1 Apparent Rennarian)Homebrewing since 1990AHA member since 1991, now a lifetime member BJCP judge since 1995